An object of the present invention is to provide a fuel injector which can promote convergence of a motion of a valve body while a valve is opened and promote stabilization of an injection amount. In the present invention, a fuel injector includes a movable iron core 404, a fixed iron core 401, a first spring member 405, a second spring member 406, contact portions 102c and 404b′, and a gap g1. The movable iron core 404 is provided relatively displaceable to a valve body 102. The fixed iron core 401 is opposed to the movable iron core 404. The first spring member 405 energizes the valve body 102 in a valve closing direction. The second spring member 406 energizes the movable iron core 404 in a valve closing direction. The contact portions 102c and 404b′ are in contact with each other in a case where the movable iron core 404 displaces in a valve opening direction with respect to the valve body 102. The gap g1 is formed between the contact portions 102c and 404b′ in a valve closing state. In a state in which the movable iron core 404 and the valve body 102 move in different directions after the movable iron core 404 collides with the fixed iron core 401 while a valve is opened, a spring force is not applied between the movable iron core 404 and the valve body 102.

An object of the present invention is to provide a fuel injector which can promote convergence of a motion of a valve body while a valve is opened and promote stabilization of an injection amount. In the present invention, a fuel injector includes a movable iron core 404, a fixed iron core 401, a first spring member 405, a second spring member 406, contact portions 102c and 404b′, and a gap g1. The movable iron core 404 is provided relatively displaceable to a valve body 102. The fixed iron core 401 is opposed to the movable iron core 404. The first spring member 405 energizes the valve body 102 in a valve closing direction. The second spring member 406 energizes the movable iron core 404 in a valve closing direction. The contact portions 102c and 404b′ are in contact with each other in a case where the movable iron core 404 displaces in a valve opening direction with respect to the valve body 102. The gap g1 is formed between the contact portions 102c and 404b′ in a valve closing state. In a state in which the movable iron core 404 and the valve body 102 move in different directions after the movable iron core 404 collides with the fixed iron core 401 while a valve is opened, a spring force is not applied between the movable iron core 404 and the valve body 102.

A fuel injector is provided that creates variable spray characteristics to effectively reduce emissions, such as NOx emissions and particulate matter. The injector includes a nozzle valve element of the outwardly opening type including a fuel delivery passage and spray holes. The nozzle valve element is operable to move to a low lift position to cause fuel flowing from the spray holes to impinge on the injector body and to deflect toward the combustion chamber, and to move to a high lift position to cause fuel flowing from the spray holes to avoid impingement on injector body and flow in an obstructed manner directly into the combustion chamber. An annular chamber may be formed in the nozzle valve element adjacent the spray holes to receive fuel.

A fuel system for an internal combustion engine includes an actuation train having a cam follower, a pushrod, a rocker arm, and a camshaft having a cam lobe rotatable in contact with the cam follower according to an ascending ramp phasing, a peak phasing, and a descending ramp phasing. The fuel system further includes a fuel injector including an electrically actuated spill valve. A fueling control unit is in communication with the spill valve and structured to close the spill valve during the ascending ramp phasing, such that a plunger cavity pressure is increased to oppose a plunger-advancement inertia of the actuation train. Related methodology and control logic is also disclosed.

A fuel injection device for an internal combustion engine including a cylinder, includes a fuel injection valve and a processor. The fuel injection valve injects fuel directly into the cylinder. The fuel injection valve has an injection hole which has a diameter and a length in an axial direction of the injection hole. A ratio of the length to the diameter being 1.0 or smaller. The processor is configured to determine, in a cold operation of the internal combustion engine, a fuel injection time during which the fuel injection valve continues to inject fuel such that an amount of soot in exhaust gas is less than an amount of soot in exhaust gas if the fuel injection valve has the ratio larger than 1.0.

An engine including a main fuel injection valve, a pilot fuel injection valve, a liquid fuel supply rail pipe, and a pilot fuel supply rail pipe. The main fuel injection valve supplies liquid fuel from the liquid fuel supply rail pipe to a combustion chamber during combustion in a diffusion combustion system. The pilot fuel injection valve supplies pilot fuel from the pilot fuel supply rail pipe to the combustion chamber in order to ignite gaseous fuel during combustion in a premixed combustion system. The liquid fuel supply rail pipe is disposed at one side of an imaginary vertical plane (P1) including an axis of a crank shaft. The pilot fuel supply rail pipe is disposed at the side of the imaginary vertical plane at which the liquid fuel supply rail pipe is disposed.

An engine including a main fuel injection valve, a pilot fuel injection valve, a liquid fuel supply rail pipe, and a pilot fuel supply rail pipe. The main fuel injection valve supplies liquid fuel from the liquid fuel supply rail pipe to a combustion chamber during combustion in a diffusion combustion system. The pilot fuel injection valve supplies pilot fuel from the pilot fuel supply rail pipe to the combustion chamber in order to ignite gaseous fuel during combustion in a premixed combustion system. The liquid fuel supply rail pipe is disposed at one side of an imaginary vertical plane (P1) including an axis of a crank shaft. The pilot fuel supply rail pipe is disposed at the side of the imaginary vertical plane at which the liquid fuel supply rail pipe is disposed.

A fuel injection valve drive control device includes a boost circuit having a boost coil, a switching component (FFT or the like) supplying a switching current from a battery source voltage to the boost coil, and a boost capacitor accumulating a boosted voltage generated by the operation of the switching component; a discharge circuit for discharging the accumulated electric charge via a current limiter (e.g. discharge resistor, constant current source) and a discharge switch (FET or the like); and a monitoring circuit for monitoring the accumulated voltage. The discharge circuit is caused to operate when the control device is shutting down and performs a deterioration/failure diagnosis of the boost capacitor and an operation check of the discharge circuit on the basis of a monitored voltage value of the boost capacitor at starting the discharge operation and a monitored voltage value of the boost capacitor after a predetermined time has elapsed.

A fuel injection valve drive control device includes a boost circuit having a boost coil, a switching component (FFT or the like) supplying a switching current from a battery source voltage to the boost coil, and a boost capacitor accumulating a boosted voltage generated by the operation of the switching component; a discharge circuit for discharging the accumulated electric charge via a current limiter (e.g. discharge resistor, constant current source) and a discharge switch (FET or the like); and a monitoring circuit for monitoring the accumulated voltage. The discharge circuit is caused to operate when the control device is shutting down and performs a deterioration/failure diagnosis of the boost capacitor and an operation check of the discharge circuit on the basis of a monitored voltage value of the boost capacitor at starting the discharge operation and a monitored voltage value of the boost capacitor after a predetermined time has elapsed.

Exemplary fuel injectors for use in fuel injection devices are disclosed. An injector may have a control chamber, which can be selectively relieved of pressure by means of a pilot valve in order to control a nozzle needle stroke of an axially displaceable nozzle needle of the injector. The fuel injector may have at least one nozzle on a first end, and the control chamber on a second end of the nozzle needle. The control chamber may be sub-divided by a throttle plate accommodated therein into a first chamber and a second chamber, with the second chamber being positioned closer to the nozzle, and the two chambers communicating with each other via the throttle plate. First and second resilient elements may be accommodated in a pre-stressed manner against the throttle plate in the first chamber and in the second chamber, respectively.